


i'm going to hell (who's coming with me?)

by golden_goose



Category: It's Always Sunny in Philadelphia
Genre: Double Penetration, F/M, M/M, Multi, Oral Sex, Sibling Incest, Threesome - F/M/M, Twincest
Language: English
Status: Completed
Published: 2017-10-18
Updated: 2017-10-18
Packaged: 2019-01-18 23:58:14
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,186
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12398901
Author URL: https://archiveofourown.org/users/golden_goose/pseuds/golden_goose
Summary: Dennis talks Mac into a three-way





	i'm going to hell (who's coming with me?)

**Author's Note:**

  * For [haemophilus](https://archiveofourown.org/users/haemophilus/gifts).



“I can’t believe I let you talk me into this.”

Dennis lifted his head from between Dee's legs and turned to face his friend.

“Oh, you gotta trust me Mac, it’s amazing. You get to be inside a hot chick with another dick sliding against yours. It’s the best of both worlds."

The thought of Dennis’s cock sliding against his own was enough to make Mac blush. The whole situation was weird as hell ( _why did Dennis want to bang his sister?_ ), but Mac was just drunk enough to agree to _try_ after an hour of begging from Dennis.

Dee shoved Dennis’s head back down, impatient, “That’s enough talking, you two.”

Mac went silent. Dee was still gross, and Dennis was still her brother, but watching him enthusiastically eating her out was surprisingly hot. Dennis was getting hard, too--the tented front of his boxers just barely visible in the dim light--from eating out _Dee_ of all people. It was one of the most fucked up things he’d ever seen, but (God forgive him), Mac shifted uncomfortably and let out a whimper as he felt his cock start to swell.

Dennis pulled off again, much to Dee’s frustration.

“Touch yourself,” he demanded.

“This is so gross,” Mac muttered as he hesitantly palmed himself.

“Just do it, Mac,” Dee gritted out, wrapping a leg behind Dennis’s neck to keep him in place as he returned to mouth at her clit.

Mac closed his eyes, trying to ignore the shrill noises Dee was making as she got closer and closer to orgasm. Instead he focused on Dennis’s moans, trying to picture his friend’s talented mouth around his cock. That was enough to get Mac going, spitting in his palm before taking his dick in hand and beginning to stroke himself.

His fantasy was rudely interrupted by a piercing shriek from Dee.

“Oh my god, _Dennis_. Don’t fucking stop. _Oh my god_. I’m gonna cum.”

She kept going, shouting nonsense until with a final curl of Dennis’s fingers and a brush of his tongue, she was gone. He kept going, too, until Dee had to shove him away to get him to stop. She pressed her thighs shut when he shifted to touch her again.

“Fuck, Dennis, enough! Go play with your boyfriend. I need a minute,” she said, staring straight at Mac.

Dennis turned to look at Mac, licking his sister’s juices off his lips. It was fucking _disgusting_ , but Mac was dying for a taste.

“Dennis,” Mac whispered as Dennis rose from the ground and slowly walked towards him, “what um...what are we doing here?”

“You,” Dennis said, in his best sultry voice, “are about to have the greatest sexual experience of your life.”

To Mac’s surprise, Dennis leaned in for a filthy kiss. He kissed like a high schooler--too much tongue and teeth, wet and sloppy so that Mac got a good taste of Dee. It didn’t even matter; Mac was already too far gone to care, moaning into Dennis’s mouth as he groped at the other man’s crotch, trying desperately to free his cock.

Dennis broke the kiss, laughing, freeing himself before guiding Mac’s fingers to curl around his dick.

“You two are lucky that you have a sex god like myself to guide you,” Dennis said.

“Whatever, bro. I have way more experience with dudes than you ‘cause I’m actually gay,” Mac shot back.

“Shut up. Both of you,” Dee squawked from the corner.

Mac grimaced a little when he remembered what they were about to do. What _he_ was about to do. To Dee.

Dennis moved back towards his twin, pulling her off the bed for a brief kiss, while Mac stayed put, still unsure.

“Are you sure we’ll both fit?” he asked.

“She squeezed a baby out of there. I think we’ll be OK,” Dennis responded with a chuckle.

Annoyed, Dee shoved him so hard that he almost fell. Dennis was flailing pathetically, and Mac couldn’t stop himself from laughing. Dee smirked in response and pushed her brother onto his back.

“Strip and come join the fun,” she said, beckoning Mac with one hand.

Dennis leaned up off of the bed, adding, “Don’t you want to fuck Dee’s pussy with me? It’ll feel so good--it’s like frottage but better because it’s hot and tight…”

“OK, OK! Fine,” Mac said, kicking off his boxers, “I’ll join you. Stop talking about your sister’s pussy though dude. Shit’s nasty.”

Dee straddled Dennis, positioning herself so he could ease into her.

Mac stood by, unsure of what to do.

“Grab the lube,” Dee instructed, “make sure you get your dick nice and slick.”

Mac did exactly as she ordered before lining himself up behind her. He pushed in slowly--Dee was almost unbearably tight with Dennis already inside her. Mac’s eyes squeezed shut and he grabbed her hip hard enough to bruise. She didn’t seem to mind though, just dropped her head to whine into Dennis’s chest.

“ _Fuck_ , Dennis, you were right. This feels so good.”

“I told you,” Dennis said smugly.

Dee pressed a hand against his mouth. “For shit’s sake,” she said, “Mac, just fuck me already.”

And shit, Dennis with Dee’s hand silencing him was even hotter than Dennis moaning into her cunt. That thought was all the encouragement Mac needed to start moving against Dennis, enjoying the way his friend was whimpering against Dee’s palm while she continued to gasp and whine against her brother.

“That’s so good Mac, keep going,” she murmured, “this is so hot.”

Mac made a strained sound of agreement, trying to think of anything but the fact that his cock was currently rutting against Dennis’s, leaking all over him, slick with his sister’s cum.

Dee gripped her brother’s hand, leading him down to rub circles around her clit. Mac felt her tighten and heard a choked sound escaped from Dennis’s mouth.

“I’m getting close and you’re not finishing before me. You don’t cum until I say you can, understand?” she said, staring straight into his eyes. Without looking back she added, “Stay still Mac.”

Mac waited patiently while Dennis rubbed her expertly, and within minutes she was teetering on the brink again, and leaning down to bite his lip. Mac grabbed her hips to steady himself, and that was all it took for her to cum again, tightening around both him and Dennis.

Dennis was practically wailing at this point, and Mac could feel his friend’s cock twitching against him and _fuck him_ it was _too fucking good_...

He came inside of Dee before she was even finished with her own orgasm, slumping forwards to rest against her back and see Dennis beneath both of them, looking up at Dee with pleading eyes. She removed her hand, finally, allowing him to speak.

“Dee, please, let me cum. I need it so bad, sis,” he begged.

“Yeah? You want it?” she asked, teasing.

“Please, please, please, Sweet Dee, you gotta let me cum,” Dennis said.

Dee took some time, pretending to consider it, before finally saying, “Cum for me. I want to see it.”


End file.
